path: root/Python/sysmodule.c

/* System module */

/*
Various bits of information used by the interpreter are collected in
module 'sys'.
Function member:
- exit(sts): raise SystemExit
Data members:
- stdin, stdout, stderr: standard file objects
- modules: the table of modules (dictionary)
- path: module search path (list of strings)
- argv: script arguments (list of strings)
- ps1, ps2: optional primary and secondary prompts (strings)
*/

#include "Python.h"
#include "structseq.h"
#include "code.h"
#include "frameobject.h"
#include "eval.h"

#include "osdefs.h"

#ifdef MS_WINDOWS
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif /* MS_WINDOWS */

#ifdef MS_COREDLL
extern void *PyWin_DLLhModule;
/* A string loaded from the DLL at startup: */
extern const char *PyWin_DLLVersionString;
#endif

#ifdef __VMS
#include <unixlib.h>
#endif

#ifdef HAVE_LANGINFO_H
#include <locale.h>
#include <langinfo.h>
#endif

PyObject *
PySys_GetObject(const char *name)
{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *sd = tstate->interp->sysdict;
	if (sd == NULL)
		return NULL;
	return PyDict_GetItemString(sd, name);
}

int
PySys_SetObject(const char *name, PyObject *v)
{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *sd = tstate->interp->sysdict;
	if (v == NULL) {
		if (PyDict_GetItemString(sd, name) == NULL)
			return 0;
		else
			return PyDict_DelItemString(sd, name);
	}
	else
		return PyDict_SetItemString(sd, name, v);
}

static PyObject *
sys_displayhook(PyObject *self, PyObject *o)
{
	PyObject *outf;
	PyInterpreterState *interp = PyThreadState_GET()->interp;
	PyObject *modules = interp->modules;
	PyObject *builtins = PyDict_GetItemString(modules, "builtins");

	if (builtins == NULL) {
		PyErr_SetString(PyExc_RuntimeError, "lost builtins module");
		return NULL;
	}

	/* Print value except if None */
	/* After printing, also assign to '_' */
	/* Before, set '_' to None to avoid recursion */
	if (o == Py_None) {
		Py_INCREF(Py_None);
		return Py_None;
	}
	if (PyObject_SetAttrString(builtins, "_", Py_None) != 0)
		return NULL;
	outf = PySys_GetObject("stdout");
	if (outf == NULL || outf == Py_None) {
		PyErr_SetString(PyExc_RuntimeError, "lost sys.stdout");
		return NULL;
	}
	if (PyFile_WriteObject(o, outf, 0) != 0)
		return NULL;
	if (PyFile_WriteString("\n", outf) != 0)
		return NULL;
	if (PyObject_SetAttrString(builtins, "_", o) != 0)
		return NULL;
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(displayhook_doc,
"displayhook(object) -> None\n"
"\n"
"Print an object to sys.stdout and also save it in builtins.\n"
);

static PyObject *
sys_excepthook(PyObject* self, PyObject* args)
{
	PyObject *exc, *value, *tb;
	if (!PyArg_UnpackTuple(args, "excepthook", 3, 3, &exc, &value, &tb))
		return NULL;
	PyErr_Display(exc, value, tb);
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(excepthook_doc,
"excepthook(exctype, value, traceback) -> None\n"
"\n"
"Handle an exception by displaying it with a traceback on sys.stderr.\n"
);

static PyObject *
sys_exc_info(PyObject *self, PyObject *noargs)
{
	PyThreadState *tstate;
	tstate = PyThreadState_GET();
	return Py_BuildValue(
		"(OOO)",
		tstate->exc_type != NULL ? tstate->exc_type : Py_None,
		tstate->exc_value != NULL ? tstate->exc_value : Py_None,
		tstate->exc_traceback != NULL ?
			tstate->exc_traceback : Py_None);
}

PyDoc_STRVAR(exc_info_doc,
"exc_info() -> (type, value, traceback)\n\
\n\
Return information about the most recent exception caught by an except\n\
clause in the current stack frame or in an older stack frame."
);

static PyObject *
sys_exit(PyObject *self, PyObject *args)
{
	PyObject *exit_code = 0;
	if (!PyArg_UnpackTuple(args, "exit", 0, 1, &exit_code))
		return NULL;
	/* Raise SystemExit so callers may catch it or clean up. */
	PyErr_SetObject(PyExc_SystemExit, exit_code);
	return NULL;
}

PyDoc_STRVAR(exit_doc,
"exit([status])\n\
\n\
Exit the interpreter by raising SystemExit(status).\n\
If the status is omitted or None, it defaults to zero (i.e., success).\n\
If the status is numeric, it will be used as the system exit status.\n\
If it is another kind of object, it will be printed and the system\n\
exit status will be one (i.e., failure)."
);


static PyObject *
sys_getdefaultencoding(PyObject *self)
{
	return PyUnicode_FromString(PyUnicode_GetDefaultEncoding());
}

PyDoc_STRVAR(getdefaultencoding_doc,
"getdefaultencoding() -> string\n\
\n\
Return the current default string encoding used by the Unicode \n\
implementation."
);

static PyObject *
sys_setdefaultencoding(PyObject *self, PyObject *args)
{
	char *encoding;
	if (!PyArg_ParseTuple(args, "s:setdefaultencoding", &encoding))
		return NULL;
	if (PyUnicode_SetDefaultEncoding(encoding))
	    	return NULL;
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setdefaultencoding_doc,
"setdefaultencoding(encoding)\n\
\n\
Set the current default string encoding used by the Unicode implementation."
);

static PyObject *
sys_getfilesystemencoding(PyObject *self)
{
	if (Py_FileSystemDefaultEncoding)
		return PyUnicode_FromString(Py_FileSystemDefaultEncoding);
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(getfilesystemencoding_doc,
"getfilesystemencoding() -> string\n\
\n\
Return the encoding used to convert Unicode filenames in\n\
operating system filenames."
);

static PyObject *
sys_setfilesystemencoding(PyObject *self, PyObject *args)
{
	PyObject *new_encoding;
	if (!PyArg_ParseTuple(args, "U:setfilesystemencoding", &new_encoding))
		return NULL;
	if (_Py_SetFileSystemEncoding(new_encoding))
		return NULL;
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setfilesystemencoding_doc,
"setfilesystemencoding(string) -> None\n\
\n\
Set the encoding used to convert Unicode filenames in\n\
operating system filenames."
);

static PyObject *
sys_intern(PyObject *self, PyObject *args)
{
	PyObject *s;
	if (!PyArg_ParseTuple(args, "U:intern", &s))
		return NULL;
	if (PyUnicode_CheckExact(s)) {
		Py_INCREF(s);
		PyUnicode_InternInPlace(&s);
		return s;
	}
	else {
		PyErr_Format(PyExc_TypeError,
				"can't intern %.400s", s->ob_type->tp_name);
		return NULL;
	}
}

PyDoc_STRVAR(intern_doc,
"intern(string) -> string\n\
\n\
``Intern'' the given string.  This enters the string in the (global)\n\
table of interned strings whose purpose is to speed up dictionary lookups.\n\
Return the string itself or the previously interned string object with the\n\
same value.");


/*
 * Cached interned string objects used for calling the profile and
 * trace functions.  Initialized by trace_init().
 */
static PyObject *whatstrings[7] = {NULL, NULL, NULL, NULL, NULL, NULL, NULL};

static int
trace_init(void)
{
	static char *whatnames[7] = {"call", "exception", "line", "return",
					"c_call", "c_exception", "c_return"};
	PyObject *name;
	int i;
	for (i = 0; i < 7; ++i) {
		if (whatstrings[i] == NULL) {
			name = PyUnicode_InternFromString(whatnames[i]);
			if (name == NULL)
				return -1;
			whatstrings[i] = name;
                }
	}
	return 0;
}


static PyObject *
call_trampoline(PyThreadState *tstate, PyObject* callback,
		PyFrameObject *frame, int what, PyObject *arg)
{
	PyObject *args = PyTuple_New(3);
	PyObject *whatstr;
	PyObject *result;

	if (args == NULL)
		return NULL;
	Py_INCREF(frame);
	whatstr = whatstrings[what];
	Py_INCREF(whatstr);
	if (arg == NULL)
		arg = Py_None;
	Py_INCREF(arg);
	PyTuple_SET_ITEM(args, 0, (PyObject *)frame);
	PyTuple_SET_ITEM(args, 1, whatstr);
	PyTuple_SET_ITEM(args, 2, arg);

	/* call the Python-level function */
	PyFrame_FastToLocals(frame);
	result = PyEval_CallObject(callback, args);
	PyFrame_LocalsToFast(frame, 1);
	if (result == NULL)
		PyTraceBack_Here(frame);

	/* cleanup */
	Py_DECREF(args);
	return result;
}

static int
profile_trampoline(PyObject *self, PyFrameObject *frame,
		   int what, PyObject *arg)
{
	PyThreadState *tstate = frame->f_tstate;
	PyObject *result;

	if (arg == NULL)
		arg = Py_None;
	result = call_trampoline(tstate, self, frame, what, arg);
	if (result == NULL) {
		PyEval_SetProfile(NULL, NULL);
		return -1;
	}
	Py_DECREF(result);
	return 0;
}

static int
trace_trampoline(PyObject *self, PyFrameObject *frame,
		 int what, PyObject *arg)
{
	PyThreadState *tstate = frame->f_tstate;
	PyObject *callback;
	PyObject *result;

	if (what == PyTrace_CALL)
		callback = self;
	else
		callback = frame->f_trace;
	if (callback == NULL)
		return 0;
	result = call_trampoline(tstate, callback, frame, what, arg);
	if (result == NULL) {
		PyEval_SetTrace(NULL, NULL);
		Py_XDECREF(frame->f_trace);
		frame->f_trace = NULL;
		return -1;
	}
	if (result != Py_None) {
		PyObject *temp = frame->f_trace;
		frame->f_trace = NULL;
		Py_XDECREF(temp);
		frame->f_trace = result;
	}
	else {
		Py_DECREF(result);
	}
	return 0;
}

static PyObject *
sys_settrace(PyObject *self, PyObject *args)
{
	if (trace_init() == -1)
		return NULL;
	if (args == Py_None)
		PyEval_SetTrace(NULL, NULL);
	else
		PyEval_SetTrace(trace_trampoline, args);
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(settrace_doc,
"settrace(function)\n\
\n\
Set the global debug tracing function.  It will be called on each\n\
function call.  See the debugger chapter in the library manual."
);

static PyObject *
sys_gettrace(PyObject *self, PyObject *args)
{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *temp = tstate->c_traceobj;

	if (temp == NULL)
		temp = Py_None;
	Py_INCREF(temp);
	return temp;
}

PyDoc_STRVAR(gettrace_doc,
"gettrace()\n\
\n\
Return the global debug tracing function set with sys.settrace.\n\
See the debugger chapter in the library manual."
);

static PyObject *
sys_setprofile(PyObject *self, PyObject *args)
{
	if (trace_init() == -1)
		return NULL;
	if (args == Py_None)
		PyEval_SetProfile(NULL, NULL);
	else
		PyEval_SetProfile(profile_trampoline, args);
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setprofile_doc,
"setprofile(function)\n\
\n\
Set the profiling function.  It will be called on each function call\n\
and return.  See the profiler chapter in the library manual."
);

static PyObject *
sys_getprofile(PyObject *self, PyObject *args)
{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *temp = tstate->c_profileobj;

	if (temp == NULL)
		temp = Py_None;
	Py_INCREF(temp);
	return temp;
}

PyDoc_STRVAR(getprofile_doc,
"getprofile()\n\
\n\
Return the profiling function set with sys.setprofile.\n\
See the profiler chapter in the library manual."
);

static PyObject *
sys_setcheckinterval(PyObject *self, PyObject *args)
{
	if (!PyArg_ParseTuple(args, "i:setcheckinterval", &_Py_CheckInterval))
		return NULL;
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setcheckinterval_doc,
"setcheckinterval(n)\n\
\n\
Tell the Python interpreter to check for asynchronous events every\n\
n instructions.  This also affects how often thread switches occur."
);

static PyObject *
sys_getcheckinterval(PyObject *self, PyObject *args)
{
	return PyLong_FromLong(_Py_CheckInterval);
}

PyDoc_STRVAR(getcheckinterval_doc,
"getcheckinterval() -> current check interval; see setcheckinterval()."
);

#ifdef WITH_TSC
static PyObject *
sys_settscdump(PyObject *self, PyObject *args)
{
	int bool;
	PyThreadState *tstate = PyThreadState_Get();

	if (!PyArg_ParseTuple(args, "i:settscdump", &bool))
		return NULL;
	if (bool)
		tstate->interp->tscdump = 1;
	else
		tstate->interp->tscdump = 0;
	Py_INCREF(Py_None);
	return Py_None;

}

PyDoc_STRVAR(settscdump_doc,
"settscdump(bool)\n\
\n\
If true, tell the Python interpreter to dump VM measurements to\n\
stderr.  If false, turn off dump.  The measurements are based on the\n\
processor's time-stamp counter."
);
#endif /* TSC */

static PyObject *
sys_setrecursionlimit(PyObject *self, PyObject *args)
{
	int new_limit;
	if (!PyArg_ParseTuple(args, "i:setrecursionlimit", &new_limit))
		return NULL;
	if (new_limit <= 0) {
		PyErr_SetString(PyExc_ValueError,
				"recursion limit must be positive");
		return NULL;
	}
	Py_SetRecursionLimit(new_limit);
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setrecursionlimit_doc,
"setrecursionlimit(n)\n\
\n\
Set the maximum depth of the Python interpreter stack to n.  This\n\
limit prevents infinite recursion from causing an overflow of the C\n\
stack and crashing Python.  The highest possible limit is platform-\n\
dependent."
);

static PyObject *
sys_getrecursionlimit(PyObject *self)
{
	return PyLong_FromLong(Py_GetRecursionLimit());
}

PyDoc_STRVAR(getrecursionlimit_doc,
"getrecursionlimit()\n\
\n\
Return the current value of the recursion limit, the maximum depth\n\
of the Python interpreter stack.  This limit prevents infinite\n\
recursion from causing an overflow of the C stack and crashing Python."
);

#ifdef MS_WINDOWS
PyDoc_STRVAR(getwindowsversion_doc,
"getwindowsversion()\n\
\n\
Return information about the running version of Windows.\n\
The result is a tuple of (major, minor, build, platform, text)\n\
All elements are numbers, except text which is a string.\n\
Platform may be 0 for win32s, 1 for Windows 9x/ME, 2 for Windows NT/2000/XP\n\
"
);

static PyObject *
sys_getwindowsversion(PyObject *self)
{
	OSVERSIONINFO ver;
	ver.dwOSVersionInfoSize = sizeof(ver);
	if (!GetVersionEx(&ver))
		return PyErr_SetFromWindowsErr(0);
	return Py_BuildValue("HHHHs",
	                     ver.dwMajorVersion,
	                     ver.dwMinorVersion,
	                     ver.dwBuildNumber,
	                     ver.dwPlatformId,
	                     ver.szCSDVersion);
}

#endif /* MS_WINDOWS */

#ifdef HAVE_DLOPEN
static PyObject *
sys_setdlopenflags(PyObject *self, PyObject *args)
{
	int new_val;
        PyThreadState *tstate = PyThreadState_GET();
	if (!PyArg_ParseTuple(args, "i:setdlopenflags", &new_val))
		return NULL;
        if (!tstate)
		return NULL;
        tstate->interp->dlopenflags = new_val;
	Py_INCREF(Py_None);
	return Py_None;
}

PyDoc_STRVAR(setdlopenflags_doc,
"setdlopenflags(n) -> None\n\
\n\
Set the flags that will be used for dlopen() calls. Among other\n\
things, this will enable a lazy resolving of symbols when importing\n\
a module, if called as sys.setdlopenflags(0)\n\
To share symbols across extension modules, call as\n\
sys.setdlopenflags(dl.RTLD_NOW|dl.RTLD_GLOBAL)"
);

static PyObject *
sys_getdlopenflags(PyObject *self, PyObject *args)
{
        PyThreadState *tstate = PyThreadState_GET();
        if (!tstate)
		return NULL;
        return PyLong_FromLong(tstate->interp->dlopenflags);
}

PyDoc_STRVAR(getdlopenflags_doc,
"getdlopenflags() -> int\n\
\n\
Return the current value of the flags that are used for dlopen()\n\
calls. The flag constants are defined in the dl module."
);
#endif

#ifdef USE_MALLOPT
/* Link with -lmalloc (or -lmpc) on an SGI */
#include <malloc.h>

static PyObject *
sys_mdebug(PyObject *self, PyObject *args)
{
	int flag;
	if (!PyArg_ParseTuple(args, "i:mdebug", &flag))
		return NULL;
	mallopt(M_DEBUG, flag);
	Py_INCREF(Py_None);
	return Py_None;
}
#endif /* USE_MALLOPT */

static PyObject *
sys_getsizeof(PyObject *self, PyObject *args, PyObject *kwds)
{
	PyObject *res = NULL;
	static PyObject *str__sizeof__, *gc_head_size = NULL;
	static char *kwlist[] = {"object", "default", 0};
	PyObject *o, *dflt = NULL;
	PyObject *method;

	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:getsizeof",
					 kwlist, &o, &dflt))
		return NULL;

	/* Initialize static variable needed by _PyType_Lookup */
	if (str__sizeof__ == NULL) {
		str__sizeof__ = PyUnicode_InternFromString("__sizeof__");
		if (str__sizeof__ == NULL)
			return NULL;
	}

        /* Initialize static variable for GC head size */
	if (gc_head_size == NULL) {
		gc_head_size = PyLong_FromSsize_t(sizeof(PyGC_Head));
		if (gc_head_size == NULL)
			return NULL;
	}
	
	/* Make sure the type is initialized. float gets initialized late */
	if (PyType_Ready(Py_TYPE(o)) < 0)
		return NULL;
	
	method = _PyType_Lookup(Py_TYPE(o), str__sizeof__);
	if (method == NULL)
		PyErr_Format(PyExc_TypeError,
			     "Type %.100s doesn't define __sizeof__",
			     Py_TYPE(o)->tp_name);
	else
		res = PyObject_CallFunctionObjArgs(method, o, NULL);
	
	/* Has a default value been given */
	if ((res == NULL) && (dflt != NULL) &&
	    PyErr_ExceptionMatches(PyExc_TypeError))
	{
		PyErr_Clear();
		Py_INCREF(dflt);
		return dflt;
	}
	else if (res == NULL)
		return res;

	/* add gc_head size */
	if (PyObject_IS_GC(o)) {
		PyObject *tmp = res;
		res = PyNumber_Add(tmp, gc_head_size);
		Py_DECREF(tmp);
	}
	return res;
}

PyDoc_STRVAR(getsizeof_doc,
"getsizeof(object, default) -> int\n\
\n\
Return the size of object in bytes.");

static PyObject *
sys_getrefcount(PyObject *self, PyObject *arg)
{
	return PyLong_FromSsize_t(arg->ob_refcnt);
}

#ifdef Py_REF_DEBUG
static PyObject *
sys_gettotalrefcount(PyObject *self)
{
	return PyLong_FromSsize_t(_Py_GetRefTotal());
}
#endif /* Py_REF_DEBUG */

PyDoc_STRVAR(getrefcount_doc,
"getrefcount(object) -> integer\n\
\n\
Return the reference count of object.  The count returned is generally\n\
one higher than you might expect, because it includes the (temporary)\n\
reference as an argument to getrefcount()."
);

#ifdef COUNT_ALLOCS
static PyObject *
sys_getcounts(PyObject *self)
{
	extern PyObject *get_counts(void);

	return get_counts();
}
#endif

PyDoc_STRVAR(getframe_doc,
"_getframe([depth]) -> frameobject\n\
\n\
Return a frame object from the call stack.  If optional integer depth is\n\
given, return the frame object that many calls below the top of the stack.\n\
If that is deeper than the call stack, ValueError is raised.  The default\n\
for depth is zero, returning the frame at the top of the call stack.\n\
\n\
This function should be used for internal and specialized\n\
purposes only."
);

static PyObject *
sys_getframe(PyObject *self, PyObject *args)
{
	PyFrameObject *f = PyThreadState_GET()->frame;
	int depth = -1;

	if (!PyArg_ParseTuple(args, "|i:_getframe", &depth))
		return NULL;

	while (depth > 0 && f != NULL) {
		f = f->f_back;
		--depth;
	}
	if (f == NULL) {
		PyErr_SetString(PyExc_ValueError,
				"call stack is not deep enough");
		return NULL;
	}
	Py_INCREF(f);
	return (PyObject*)f;
}

PyDoc_STRVAR(current_frames_doc,
"_current_frames() -> dictionary\n\
\n\
Return a dictionary mapping each current thread T's thread id to T's\n\
current stack frame.\n\
\n\
This function should be used for specialized purposes only."
);

static PyObject *
sys_current_frames(PyObject *self, PyObject *noargs)
{
	return _PyThread_CurrentFrames();
}

PyDoc_STRVAR(call_tracing_doc,
"call_tracing(func, args) -> object\n\
\n\
Call func(*args), while tracing is enabled.  The tracing state is\n\
saved, and restored afterwards.  This is intended to be called from\n\
a debugger from a checkpoint, to recursively debug some other code."
);

static PyObject *
sys_call_tracing(PyObject *self, PyObject *args)
{
	PyObject *func, *funcargs;
	if (!PyArg_ParseTuple(args, "OO!:call_tracing", &func, &PyTuple_Type, &funcargs))
		return NULL;
	return _PyEval_CallTracing(func, funcargs);
}

PyDoc_STRVAR(callstats_doc,
"callstats() -> tuple of integers\n\
\n\
Return a tuple of function call statistics, if CALL_PROFILE was defined\n\
when Python was built.  Otherwise, return None.\n\
\n\
When enabled, this function returns detailed, implementation-specific\n\
details about the number of function calls executed. The return value is\n\
a 11-tuple where the entries in the tuple are counts of:\n\
0. all function calls\n\
1. calls to PyFunction_Type objects\n\
2. PyFunction calls that do not create an argument tuple\n\
3. PyFunction calls that do not create an argument tuple\n\
   and bypass PyEval_EvalCodeEx()\n\
4. PyMethod calls\n\
5. PyMethod calls on bound methods\n\
6. PyType calls\n\
7. PyCFunction calls\n\
8. generator calls\n\
9. All other calls\n\
10. Number of stack pops performed by call_function()"
);

#ifdef __cplusplus
extern "C" {
#endif

#ifdef Py_TRACE_REFS
/* Defined in objects.c because it uses static globals if that file */
extern PyObject *_Py_GetObjects(PyObject *, PyObject *);
#endif

#ifdef DYNAMIC_EXECUTION_PROFILE
/* Defined in ceval.c because it uses static globals if that file */
extern PyObject *_Py_GetDXProfile(PyObject *,  PyObject *);
#endif

#ifdef __cplusplus
}
#endif

static PyObject *
sys_clear_type_cache(PyObject* self, PyObject* args)
{
	PyType_ClearCache();
	Py_RETURN_NONE;
}

PyDoc_STRVAR(sys_clear_type_cache__doc__,
"_clear_type_cache() -> None\n\
Clear the internal type lookup cache.");


static PyMethodDef sys_methods[] = {
	/* Might as well keep this in alphabetic order */
	{"callstats", (PyCFunction)PyEval_GetCallStats, METH_NOARGS,
	 callstats_doc},
	{"_clear_type_cache",	sys_clear_type_cache,	  METH_NOARGS,
	 sys_clear_type_cache__doc__},
	{"_current_frames", sys_current_frames, METH_NOARGS,
	 current_frames_doc},
	{"displayhook",	sys_displayhook, METH_O, displayhook_doc},
	{"exc_info",	sys_exc_info, METH_NOARGS, exc_info_doc},
	{"excepthook",	sys_excepthook, METH_VARARGS, excepthook_doc},
	{"exit",	sys_exit, METH_VARARGS, exit_doc},
	{"getdefaultencoding", (PyCFunction)sys_getdefaultencoding,
	 METH_NOARGS, getdefaultencoding_doc},
#ifdef HAVE_DLOPEN
	{"getdlopenflags", (PyCFunction)sys_getdlopenflags, METH_NOARGS,
	 getdlopenflags_doc},
#endif
#ifdef COUNT_ALLOCS
	{"getcounts",	(PyCFunction)sys_getcounts, METH_NOARGS},
#endif
#ifdef DYNAMIC_EXECUTION_PROFILE
	{"getdxp",	_Py_GetDXProfile, METH_VARARGS},
#endif
	{"getfilesystemencoding", (PyCFunction)sys_getfilesystemencoding,
	 METH_NOARGS, getfilesystemencoding_doc},
#ifdef Py_TRACE_REFS
	{"getobjects",	_Py_GetObjects, METH_VARARGS},
#endif
#ifdef Py_REF_DEBUG
	{"gettotalrefcount", (PyCFunction)sys_gettotalrefcount, METH_NOARGS},
#endif
	{"getrefcount",	(PyCFunction)sys_getrefcount, METH_O, getrefcount_doc},
	{"getrecursionlimit", (PyCFunction)sys_getrecursionlimit, METH_NOARGS,
	 getrecursionlimit_doc},
	{"getsizeof",   (PyCFunction)sys_getsizeof,
	 METH_VARARGS | METH_KEYWORDS, getsizeof_doc},
	{"_getframe", sys_getframe, METH_VARARGS, getframe_doc},
#ifdef MS_WINDOWS
	{"getwindowsversion", (PyCFunction)sys_getwindowsversion, METH_NOARGS,
	 getwindowsversion_doc},
#endif /* MS_WINDOWS */
 	{"intern",	sys_intern,     METH_VARARGS, intern_doc},
#ifdef USE_MALLOPT
	{"mdebug",	sys_mdebug, METH_VARARGS},
#endif
	{"setdefaultencoding", sys_setdefaultencoding, METH_VARARGS,
	 setdefaultencoding_doc},
	{"setfilesystemencoding", sys_setfilesystemencoding, METH_VARARGS,
	 setfilesystemencoding_doc},
	{"setcheckinterval",	sys_setcheckinterval, METH_VARARGS,
	 setcheckinterval_doc},
	{"getcheckinterval",	sys_getcheckinterval, METH_NOARGS,
	 getcheckinterval_doc},
#ifdef HAVE_DLOPEN
	{"setdlopenflags", sys_setdlopenflags, METH_VARARGS,
	 setdlopenflags_doc},
#endif
	{"setprofile",	sys_setprofile, METH_O, setprofile_doc},
	{"getprofile",	sys_getprofile, METH_NOARGS, getprofile_doc},
	{"setrecursionlimit", sys_setrecursionlimit, METH_VARARGS,
	 setrecursionlimit_doc},
#ifdef WITH_TSC
	{"settscdump", sys_settscdump, METH_VARARGS, settscdump_doc},
#endif
	{"settrace",	sys_settrace, METH_O, settrace_doc},
	{"gettrace",	sys_gettrace, METH_NOARGS, gettrace_doc},
	{"call_tracing", sys_call_tracing, METH_VARARGS, call_tracing_doc},
	{NULL,		NULL}		/* sentinel */
};

static PyObject *
list_builtin_module_names(void)
{
	PyObject *list = PyList_New(0);
	int i;
	if (list == NULL)
		return NULL;
	for (i = 0; PyImport_Inittab[i].name != NULL; i++) {
		PyObject *name = PyUnicode_FromString(
			PyImport_Inittab[i].name);
		if (name == NULL)
			break;
		PyList_Append(list, name);
		Py_DECREF(name);
	}
	if (PyList_Sort(list) != 0) {
		Py_DECREF(list);
		list = NULL;
	}
	if (list) {
		PyObject *v = PyList_AsTuple(list);
		Py_DECREF(list);
		list = v;
	}
	return list;
}

static PyObject *warnoptions = NULL;

void
PySys_ResetWarnOptions(void)
{
	if (warnoptions == NULL || !PyList_Check(warnoptions))
		return;
	PyList_SetSlice(warnoptions, 0, PyList_GET_SIZE(warnoptions), NULL);
}

void
PySys_AddWarnOption(const wchar_t *s)
{
	PyObject *str;

	if (warnoptions == NULL || !PyList_Check(warnoptions)) {
		Py_XDECREF(warnoptions);
		warnoptions = PyList_New(0);
		if (warnoptions == NULL)
			return;
	}
	str = PyUnicode_FromWideChar(s, -1);
	if (str != NULL) {
		PyList_Append(warnoptions, str);
		Py_DECREF(str);
	}
}

int
PySys_HasWarnOptions(void)
{
    return (warnoptions != NULL && (PyList_Size(warnoptions) > 0)) ? 1 : 0;
}

/* XXX This doc string is too long to be a single string literal in VC++ 5.0.
   Two literals concatenated works just fine.  If you have a K&R compiler
   or other abomination that however *does* understand longer strings,
   get rid of the !!! comment in the middle and the quotes that surround it. */
PyDoc_VAR(sys_doc) =
PyDoc_STR(
"This module provides access to some objects used or maintained by the\n\
interpreter and to functions that interact strongly with the interpreter.\n\
\n\
Dynamic objects:\n\
\n\
argv -- command line arguments; argv[0] is the script pathname if known\n\
path -- module search path; path[0] is the script directory, else ''\n\
modules -- dictionary of loaded modules\n\
\n\
displayhook -- called to show results in an interactive session\n\
excepthook -- called to handle any uncaught exception other than SystemExit\n\
  To customize printing in an interactive session or to install a custom\n\
  top-level exception handler, assign other functions to replace these.\n\
\n\
stdin -- standard input file object; used by input()\n\
stdout -- standard output file object; used by print()\n\
stderr -- standard error object; used for error messages\n\
  By assigning other file objects (or objects that behave like files)\n\
  to these, it is possible to redirect all of the interpreter's I/O.\n\
\n\
last_type -- type of last uncaught exception\n\
last_value -- value of last uncaught exception\n\
last_traceback -- traceback of last uncaught exception\n\
  These three are only available in an interactive session after a\n\
  traceback has been printed.\n\
"
)
/* concatenating string here */
PyDoc_STR(
"\n\
Static objects:\n\
\n\
float_info -- a dict with information about the float implementation.\n\
maxsize -- the largest supported length of containers.\n\
maxunicode -- the largest supported character\n\
builtin_module_names -- tuple of module names built into this interpreter\n\
subversion -- subversion information of the build as tuple\n\
version -- the version of this interpreter as a string\n\
version_info -- version information as a tuple\n\
hexversion -- version information encoded as a single integer\n\
copyright -- copyright notice pertaining to this interpreter\n\
platform -- platform identifier\n\
executable -- pathname of this Python interpreter\n\
prefix -- prefix used to find the Python library\n\
exec_prefix -- prefix used to find the machine-specific Python library\n\
"
)
#ifdef MS_WINDOWS
/* concatenating string here */
PyDoc_STR(
"dllhandle -- [Windows only] integer handle of the Python DLL\n\
winver -- [Windows only] version number of the Python DLL\n\
"
)
#endif /* MS_WINDOWS */
PyDoc_STR(
"__stdin__ -- the original stdin; don't touch!\n\
__stdout__ -- the original stdout; don't touch!\n\
__stderr__ -- the original stderr; don't touch!\n\
__displayhook__ -- the original displayhook; don't touch!\n\
__excepthook__ -- the original excepthook; don't touch!\n\
\n\
Functions:\n\
\n\
displayhook() -- print an object to the screen, and save it in builtins._\n\
excepthook() -- print an exception and its traceback to sys.stderr\n\
exc_info() -- return thread-safe information about the current exception\n\
exit() -- exit the interpreter by raising SystemExit\n\
getdlopenflags() -- returns flags to be used for dlopen() calls\n\
getprofile() -- get the global profiling function\n\
getrefcount() -- return the reference count for an object (plus one :-)\n\
getrecursionlimit() -- return the max recursion depth for the interpreter\n\
getsizeof() -- return the size of an object in bytes\n\
gettrace() -- get the global debug tracing function\n\
setcheckinterval() -- control how often the interpreter checks for events\n\
setdlopenflags() -- set the flags to be used for dlopen() calls\n\
setprofile() -- set the global profiling function\n\
setrecursionlimit() -- set the max recursion depth for the interpreter\n\
settrace() -- set the global debug tracing function\n\
"
)
/* end of sys_doc */ ;

/* Subversion branch and revision management */
static const char _patchlevel_revision[] = PY_PATCHLEVEL_REVISION;
static const char headurl[] = "$HeadURL$";
static int svn_initialized;
static char patchlevel_revision[50]; /* Just the number */
static char branch[50];
static char shortbranch[50];
static const char *svn_revision;

static void
svnversion_init(void)
{
	const char *python, *br_start, *br_end, *br_end2, *svnversion;
	Py_ssize_t len;
	int istag = 0;

	if (svn_initialized)
		return;

	python = strstr(headurl, "/python/");
	if (!python) {
		strcpy(branch, "unknown branch");
		strcpy(shortbranch, "unknown");
	}
	else {
		br_start = python + 8;
		br_end = strchr(br_start, '/');
		assert(br_end);

		/* Works even for trunk,
		   as we are in trunk/Python/sysmodule.c */
		br_end2 = strchr(br_end+1, '/');

		istag = strncmp(br_start, "tags", 4) == 0;
		if (strncmp(br_start, "trunk", 5) == 0) {
			strcpy(branch, "trunk");
			strcpy(shortbranch, "trunk");
		}
		else if (istag || strncmp(br_start, "branches", 8) == 0) {
			len = br_end2 - br_start;
			strncpy(branch, br_start, len);
			branch[len] = '\0';

			len = br_end2 - (br_end + 1);
			strncpy(shortbranch, br_end + 1, len);
			shortbranch[len] = '\0';
		}
		else {
			Py_FatalError("bad HeadURL");
			return;
		}
	}


	svnversion = _Py_svnversion();
	if (strcmp(svnversion, "exported") != 0)
		svn_revision = svnversion;
	else if (istag) {
		len = strlen(_patchlevel_revision);
		assert(len >= 13);
		assert(len < (sizeof(patchlevel_revision) + 13));
		strncpy(patchlevel_revision, _patchlevel_revision + 11,
			len - 13);
		patchlevel_revision[len - 13] = '\0';
		svn_revision = patchlevel_revision;
	}
	else
		svn_revision = "";

	svn_initialized = 1;
}

/* Return svnversion output if available.
   Else return Revision of patchlevel.h if on branch.
   Else return empty string */
const char*
Py_SubversionRevision()
{
	svnversion_init();
	return svn_revision;
}

const char*
Py_SubversionShortBranch()
{
	svnversion_init();
	return shortbranch;
}


PyDoc_STRVAR(flags__doc__,
"sys.flags\n\
\n\
Flags provided through command line arguments or environment vars.");

static PyTypeObject FlagsType;

static PyStructSequence_Field flags_fields[] = {
	{"debug",		"-d"},
	{"division_warning",	"-Q"},
	{"inspect",		"-i"},
	{"interactive",		"-i"},
	{"optimize",		"-O or -OO"},
	{"dont_write_bytecode",	"-B"},
	{"no_user_site",	"-s"},
	{"no_site",		"-S"},
	{"ignore_environment",	"-E"},
	{"verbose",		"-v"},
#ifdef RISCOS
	{"riscos_wimp",		"???"},
#endif
	/* {"unbuffered",		"-u"}, */
	/* {"skip_first",		"-x"}, */
	{"bytes_warning", "-b"},
	{0}
};

static PyStructSequence_Desc flags_desc = {
	"sys.flags",	/* name */
	flags__doc__,	/* doc */
	flags_fields,	/* fields */
#ifdef RISCOS
	12
#else
	11
#endif
};

static PyObject*
make_flags(void)
{
	int pos = 0;
	PyObject *seq;

	seq = PyStructSequence_New(&FlagsType);
	if (seq == NULL)
		return NULL;

#define SetFlag(flag) \
	PyStructSequence_SET_ITEM(seq, pos++, PyLong_FromLong(flag))

	SetFlag(Py_DebugFlag);
	SetFlag(Py_DivisionWarningFlag);
	SetFlag(Py_InspectFlag);
	SetFlag(Py_InteractiveFlag);
	SetFlag(Py_OptimizeFlag);
	SetFlag(Py_DontWriteBytecodeFlag);
	SetFlag(Py_NoUserSiteDirectory);
	SetFlag(Py_NoSiteFlag);
	SetFlag(Py_IgnoreEnvironmentFlag);
	SetFlag(Py_VerboseFlag);
#ifdef RISCOS
	SetFlag(Py_RISCOSWimpFlag);
#endif
	/* SetFlag(saw_unbuffered_flag); */
	/* SetFlag(skipfirstline); */
    SetFlag(Py_BytesWarningFlag);
#undef SetFlag

	if (PyErr_Occurred()) {
		return NULL;
	}
	return seq;
}

static struct PyModuleDef sysmodule = {
	PyModuleDef_HEAD_INIT,
	"sys",
	sys_doc,
	-1, /* multiple "initialization" just copies the module dict. */
	sys_methods,
	NULL,
	NULL,
	NULL,
	NULL
};
invalid character on encoding error.

   Use the Py_DecodeLocale() function to decode the bytes string back to a wide
   character string. */
char*
Py_EncodeLocale(const wchar_t *text, size_t *error_pos)
{
    return encode_locale(text, error_pos, 0, 0);
}


/* Similar to Py_EncodeLocale(), but result must be freed by PyMem_RawFree()
   instead of PyMem_Free(). */
char*
_Py_EncodeLocaleRaw(const wchar_t *text, size_t *error_pos)
{
    return encode_locale(text, error_pos, 1, 0);
}


int
_Py_EncodeLocaleEx(const wchar_t *text, char **str,
                   size_t *error_pos, const char **reason,
                   int current_locale, _Py_error_handler errors)
{
    return encode_locale_ex(text, str, error_pos, reason, 1,
                            current_locale, errors);
}


// Get the current locale encoding name:
//
// - Return "utf-8" if _Py_FORCE_UTF8_LOCALE macro is defined (ex: on Android)
// - Return "utf-8" if the UTF-8 Mode is enabled
// - On Windows, return the ANSI code page (ex: "cp1250")
// - Return "utf-8" if nl_langinfo(CODESET) returns an empty string.
// - Otherwise, return nl_langinfo(CODESET).
//
// Return NULL on memory allocation failure.
//
// See also config_get_locale_encoding()
wchar_t*
_Py_GetLocaleEncoding(void)
{
#ifdef _Py_FORCE_UTF8_LOCALE
    // On Android langinfo.h and CODESET are missing,
    // and UTF-8 is always used in mbstowcs() and wcstombs().
    return _PyMem_RawWcsdup(L"utf-8");
#else

#ifdef MS_WINDOWS
    wchar_t encoding[23];
    unsigned int ansi_codepage = GetACP();
    swprintf(encoding, Py_ARRAY_LENGTH(encoding), L"cp%u", ansi_codepage);
    encoding[Py_ARRAY_LENGTH(encoding) - 1] = 0;
    return _PyMem_RawWcsdup(encoding);
#else
    const char *encoding = nl_langinfo(CODESET);
    if (!encoding || encoding[0] == '\0') {
        // Use UTF-8 if nl_langinfo() returns an empty string. It can happen on
        // macOS if the LC_CTYPE locale is not supported.
        return _PyMem_RawWcsdup(L"utf-8");
    }

    wchar_t *wstr;
    int res = decode_current_locale(encoding, &wstr, NULL,
                                    NULL, _Py_ERROR_SURROGATEESCAPE);
    if (res < 0) {
        return NULL;
    }
    return wstr;
#endif  // !MS_WINDOWS

#endif  // !_Py_FORCE_UTF8_LOCALE
}


PyObject *
_Py_GetLocaleEncodingObject(void)
{
    wchar_t *encoding = _Py_GetLocaleEncoding();
    if (encoding == NULL) {
        PyErr_NoMemory();
        return NULL;
    }

    PyObject *str = PyUnicode_FromWideChar(encoding, -1);
    PyMem_RawFree(encoding);
    return str;
}

#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION

/* Check whether current locale uses Unicode as internal wchar_t form. */
int
_Py_LocaleUsesNonUnicodeWchar(void)
{
    /* Oracle Solaris uses non-Unicode internal wchar_t form for
       non-Unicode locales and hence needs conversion to UTF first. */
    char* codeset = nl_langinfo(CODESET);
    if (!codeset) {
        return 0;
    }
    /* 646 refers to ISO/IEC 646 standard that corresponds to ASCII encoding */
    return (strcmp(codeset, "UTF-8") != 0 && strcmp(codeset, "646") != 0);
}

static wchar_t *
_Py_ConvertWCharForm(const wchar_t *source, Py_ssize_t size,
                     const char *tocode, const char *fromcode)
{
    static_assert(sizeof(wchar_t) == 4, "wchar_t must be 32-bit");

    /* Ensure we won't overflow the size. */
    if (size > (PY_SSIZE_T_MAX / (Py_ssize_t)sizeof(wchar_t))) {
        PyErr_NoMemory();
        return NULL;
    }

    /* the string doesn't have to be NULL terminated */
    wchar_t* target = PyMem_Malloc(size * sizeof(wchar_t));
    if (target == NULL) {
        PyErr_NoMemory();
        return NULL;
    }

    iconv_t cd = iconv_open(tocode, fromcode);
    if (cd == (iconv_t)-1) {
        PyErr_Format(PyExc_ValueError, "iconv_open() failed");
        PyMem_Free(target);
        return NULL;
    }

    char *inbuf = (char *) source;
    char *outbuf = (char *) target;
    size_t inbytesleft = sizeof(wchar_t) * size;
    size_t outbytesleft = inbytesleft;

    size_t ret = iconv(cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft);
    if (ret == DECODE_ERROR) {
        PyErr_Format(PyExc_ValueError, "iconv() failed");
        PyMem_Free(target);
        iconv_close(cd);
        return NULL;
    }

    iconv_close(cd);
    return target;
}

/* Convert a wide character string to the UCS-4 encoded string. This
   is necessary on systems where internal form of wchar_t are not Unicode
   code points (e.g. Oracle Solaris).

   Return a pointer to a newly allocated string, use PyMem_Free() to free
   the memory. Return NULL and raise exception on conversion or memory
   allocation error. */
wchar_t *
_Py_DecodeNonUnicodeWchar(const wchar_t *native, Py_ssize_t size)
{
    return _Py_ConvertWCharForm(native, size, "UCS-4-INTERNAL", "wchar_t");
}

/* Convert a UCS-4 encoded string to native wide character string. This
   is necessary on systems where internal form of wchar_t are not Unicode
   code points (e.g. Oracle Solaris).

   The conversion is done in place. This can be done because both wchar_t
   and UCS-4 use 4-byte encoding, and one wchar_t symbol always correspond
   to a single UCS-4 symbol and vice versa. (This is true for Oracle Solaris,
   which is currently the only system using these functions; it doesn't have
   to be for other systems).

   Return 0 on success. Return -1 and raise exception on conversion
   or memory allocation error. */
int
_Py_EncodeNonUnicodeWchar_InPlace(wchar_t *unicode, Py_ssize_t size)
{
    wchar_t* result = _Py_ConvertWCharForm(unicode, size, "wchar_t", "UCS-4-INTERNAL");
    if (!result) {
        return -1;
    }
    memcpy(unicode, result, size * sizeof(wchar_t));
    PyMem_Free(result);
    return 0;
}
#endif /* HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION */

#ifdef MS_WINDOWS
static __int64 secs_between_epochs = 11644473600; /* Seconds between 1.1.1601 and 1.1.1970 */

static void
FILE_TIME_to_time_t_nsec(FILETIME *in_ptr, time_t *time_out, int* nsec_out)
{
    /* XXX endianness. Shouldn't matter, as all Windows implementations are little-endian */
    /* Cannot simply cast and dereference in_ptr,
       since it might not be aligned properly */
    __int64 in;
    memcpy(&in, in_ptr, sizeof(in));
    *nsec_out = (int)(in % 10000000) * 100; /* FILETIME is in units of 100 nsec. */
    *time_out = Py_SAFE_DOWNCAST((in / 10000000) - secs_between_epochs, __int64, time_t);
}

void
_Py_time_t_to_FILE_TIME(time_t time_in, int nsec_in, FILETIME *out_ptr)
{
    /* XXX endianness */
    __int64 out;
    out = time_in + secs_between_epochs;
    out = out * 10000000 + nsec_in / 100;
    memcpy(out_ptr, &out, sizeof(out));
}

/* Below, we *know* that ugo+r is 0444 */
#if _S_IREAD != 0400
#error Unsupported C library
#endif
static int
attributes_to_mode(DWORD attr)
{
    int m = 0;
    if (attr & FILE_ATTRIBUTE_DIRECTORY)
        m |= _S_IFDIR | 0111; /* IFEXEC for user,group,other */
    else
        m |= _S_IFREG;
    if (attr & FILE_ATTRIBUTE_READONLY)
        m |= 0444;
    else
        m |= 0666;
    return m;
}

void
_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
                           struct _Py_stat_struct *result)
{
    memset(result, 0, sizeof(*result));
    result->st_mode = attributes_to_mode(info->dwFileAttributes);
    result->st_size = (((__int64)info->nFileSizeHigh)<<32) + info->nFileSizeLow;
    result->st_dev = info->dwVolumeSerialNumber;
    result->st_rdev = result->st_dev;
    FILE_TIME_to_time_t_nsec(&info->ftCreationTime, &result->st_ctime, &result->st_ctime_nsec);
    FILE_TIME_to_time_t_nsec(&info->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
    FILE_TIME_to_time_t_nsec(&info->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);
    result->st_nlink = info->nNumberOfLinks;
    result->st_ino = (((uint64_t)info->nFileIndexHigh) << 32) + info->nFileIndexLow;
    /* bpo-37834: Only actual symlinks set the S_IFLNK flag. But lstat() will
       open other name surrogate reparse points without traversing them. To
       detect/handle these, check st_file_attributes and st_reparse_tag. */
    result->st_reparse_tag = reparse_tag;
    if (info->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
        reparse_tag == IO_REPARSE_TAG_SYMLINK) {
        /* first clear the S_IFMT bits */
        result->st_mode ^= (result->st_mode & S_IFMT);
        /* now set the bits that make this a symlink */
        result->st_mode |= S_IFLNK;
    }
    result->st_file_attributes = info->dwFileAttributes;
}
#endif

/* Return information about a file.

   On POSIX, use fstat().

   On Windows, use GetFileType() and GetFileInformationByHandle() which support
   files larger than 2 GiB.  fstat() may fail with EOVERFLOW on files larger
   than 2 GiB because the file size type is a signed 32-bit integer: see issue
   #23152.

   On Windows, set the last Windows error and return nonzero on error. On
   POSIX, set errno and return nonzero on error. Fill status and return 0 on
   success. */
int
_Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
{
#ifdef MS_WINDOWS
    BY_HANDLE_FILE_INFORMATION info;
    HANDLE h;
    int type;

    h = _Py_get_osfhandle_noraise(fd);

    if (h == INVALID_HANDLE_VALUE) {
        /* errno is already set by _get_osfhandle, but we also set
           the Win32 error for callers who expect that */
        SetLastError(ERROR_INVALID_HANDLE);
        return -1;
    }
    memset(status, 0, sizeof(*status));

    type = GetFileType(h);
    if (type == FILE_TYPE_UNKNOWN) {
        DWORD error = GetLastError();
        if (error != 0) {
            errno = winerror_to_errno(error);
            return -1;
        }
        /* else: valid but unknown file */
    }

    if (type != FILE_TYPE_DISK) {
        if (type == FILE_TYPE_CHAR)
            status->st_mode = _S_IFCHR;
        else if (type == FILE_TYPE_PIPE)
            status->st_mode = _S_IFIFO;
        return 0;
    }

    if (!GetFileInformationByHandle(h, &info)) {
        /* The Win32 error is already set, but we also set errno for
           callers who expect it */
        errno = winerror_to_errno(GetLastError());
        return -1;
    }

    _Py_attribute_data_to_stat(&info, 0, status);
    return 0;
#else
    return fstat(fd, status);
#endif
}

/* Return information about a file.

   On POSIX, use fstat().

   On Windows, use GetFileType() and GetFileInformationByHandle() which support
   files larger than 2 GiB.  fstat() may fail with EOVERFLOW on files larger
   than 2 GiB because the file size type is a signed 32-bit integer: see issue
   #23152.

   Raise an exception and return -1 on error. On Windows, set the last Windows
   error on error. On POSIX, set errno on error. Fill status and return 0 on
   success.

   Release the GIL to call GetFileType() and GetFileInformationByHandle(), or
   to call fstat(). The caller must hold the GIL. */
int
_Py_fstat(int fd, struct _Py_stat_struct *status)
{
    int res;

    assert(PyGILState_Check());

    Py_BEGIN_ALLOW_THREADS
    res = _Py_fstat_noraise(fd, status);
    Py_END_ALLOW_THREADS

    if (res != 0) {
#ifdef MS_WINDOWS
        PyErr_SetFromWindowsErr(0);
#else
        PyErr_SetFromErrno(PyExc_OSError);
#endif
        return -1;
    }
    return 0;
}

/* Like _Py_stat() but with a raw filename. */
int
_Py_wstat(const wchar_t* path, struct stat *buf)
{
    int err;
#ifdef MS_WINDOWS
    struct _stat wstatbuf;
    err = _wstat(path, &wstatbuf);
    if (!err) {
        buf->st_mode = wstatbuf.st_mode;
    }
#else
    char *fname;
    fname = _Py_EncodeLocaleRaw(path, NULL);
    if (fname == NULL) {
        errno = EINVAL;
        return -1;
    }
    err = stat(fname, buf);
    PyMem_RawFree(fname);
#endif
    return err;
}


/* Call _wstat() on Windows, or encode the path to the filesystem encoding and
   call stat() otherwise. Only fill st_mode attribute on Windows.

   Return 0 on success, -1 on _wstat() / stat() error, -2 if an exception was
   raised. */

int
_Py_stat(PyObject *path, struct stat *statbuf)
{
#ifdef MS_WINDOWS
    int err;

    wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
    if (wpath == NULL)
        return -2;

    err = _Py_wstat(wpath, statbuf);
    PyMem_Free(wpath);
    return err;
#else
    int ret;
    PyObject *bytes;
    char *cpath;

    bytes = PyUnicode_EncodeFSDefault(path);
    if (bytes == NULL)
        return -2;

    /* check for embedded null bytes */
    if (PyBytes_AsStringAndSize(bytes, &cpath, NULL) == -1) {
        Py_DECREF(bytes);
        return -2;
    }

    ret = stat(cpath, statbuf);
    Py_DECREF(bytes);
    return ret;
#endif
}

#ifdef MS_WINDOWS
// For some Windows API partitions, SetHandleInformation() is declared
// but none of the handle flags are defined.
#ifndef HANDLE_FLAG_INHERIT
#define HANDLE_FLAG_INHERIT 0x00000001
#endif
#endif

/* This function MUST be kept async-signal-safe on POSIX when raise=0. */
static int
get_inheritable(int fd, int raise)
{
#ifdef MS_WINDOWS
    HANDLE handle;
    DWORD flags;

    handle = _Py_get_osfhandle_noraise(fd);
    if (handle == INVALID_HANDLE_VALUE) {
        if (raise)
            PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    if (!GetHandleInformation(handle, &flags)) {
        if (raise)
            PyErr_SetFromWindowsErr(0);
        return -1;
    }

    return (flags & HANDLE_FLAG_INHERIT);
#else
    int flags;

    flags = fcntl(fd, F_GETFD, 0);
    if (flags == -1) {
        if (raise)
            PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }
    return !(flags & FD_CLOEXEC);
#endif
}

/* Get the inheritable flag of the specified file descriptor.
   Return 1 if the file descriptor can be inherited, 0 if it cannot,
   raise an exception and return -1 on error. */
int
_Py_get_inheritable(int fd)
{
    return get_inheritable(fd, 1);
}


/* This function MUST be kept async-signal-safe on POSIX when raise=0. */
static int
set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)
{
#ifdef MS_WINDOWS
    HANDLE handle;
    DWORD flags;
#else
#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
    static int ioctl_works = -1;
    int request;
    int err;
#endif
    int flags, new_flags;
    int res;
#endif

    /* atomic_flag_works can only be used to make the file descriptor
       non-inheritable */
    assert(!(atomic_flag_works != NULL && inheritable));

    if (atomic_flag_works != NULL && !inheritable) {
        if (*atomic_flag_works == -1) {
            int isInheritable = get_inheritable(fd, raise);
            if (isInheritable == -1)
                return -1;
            *atomic_flag_works = !isInheritable;
        }

        if (*atomic_flag_works)
            return 0;
    }

#ifdef MS_WINDOWS
    handle = _Py_get_osfhandle_noraise(fd);
    if (handle == INVALID_HANDLE_VALUE) {
        if (raise)
            PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    if (inheritable)
        flags = HANDLE_FLAG_INHERIT;
    else
        flags = 0;

    if (!SetHandleInformation(handle, HANDLE_FLAG_INHERIT, flags)) {
        if (raise)
            PyErr_SetFromWindowsErr(0);
        return -1;
    }
    return 0;

#else

#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
    if (ioctl_works != 0 && raise != 0) {
        /* fast-path: ioctl() only requires one syscall */
        /* caveat: raise=0 is an indicator that we must be async-signal-safe
         * thus avoid using ioctl() so we skip the fast-path. */
        if (inheritable)
            request = FIONCLEX;
        else
            request = FIOCLEX;
        err = ioctl(fd, request, NULL);
        if (!err) {
            ioctl_works = 1;
            return 0;
        }

#ifdef O_PATH
        if (errno == EBADF) {
            // bpo-44849: On Linux and FreeBSD, ioctl(FIOCLEX) fails with EBADF
            // on O_PATH file descriptors. Fall through to the fcntl()
            // implementation.
        }
        else
#endif
        if (errno != ENOTTY && errno != EACCES) {
            if (raise)
                PyErr_SetFromErrno(PyExc_OSError);
            return -1;
        }
        else {
            /* Issue #22258: Here, ENOTTY means "Inappropriate ioctl for
               device". The ioctl is declared but not supported by the kernel.
               Remember that ioctl() doesn't work. It is the case on
               Illumos-based OS for example.

               Issue #27057: When SELinux policy disallows ioctl it will fail
               with EACCES. While FIOCLEX is safe operation it may be
               unavailable because ioctl was denied altogether.
               This can be the case on Android. */
            ioctl_works = 0;
        }
        /* fallback to fcntl() if ioctl() does not work */
    }
#endif

    /* slow-path: fcntl() requires two syscalls */
    flags = fcntl(fd, F_GETFD);
    if (flags < 0) {
        if (raise)
            PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    if (inheritable) {
        new_flags = flags & ~FD_CLOEXEC;
    }
    else {
        new_flags = flags | FD_CLOEXEC;
    }

    if (new_flags == flags) {
        /* FD_CLOEXEC flag already set/cleared: nothing to do */
        return 0;
    }

    res = fcntl(fd, F_SETFD, new_flags);
    if (res < 0) {
        if (raise)
            PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }
    return 0;
#endif
}

/* Make the file descriptor non-inheritable.
   Return 0 on success, set errno and return -1 on error. */
static int
make_non_inheritable(int fd)
{
    return set_inheritable(fd, 0, 0, NULL);
}

/* Set the inheritable flag of the specified file descriptor.
   On success: return 0, on error: raise an exception and return -1.

   If atomic_flag_works is not NULL:

    * if *atomic_flag_works==-1, check if the inheritable is set on the file
      descriptor: if yes, set *atomic_flag_works to 1, otherwise set to 0 and
      set the inheritable flag
    * if *atomic_flag_works==1: do nothing
    * if *atomic_flag_works==0: set inheritable flag to False

   Set atomic_flag_works to NULL if no atomic flag was used to create the
   file descriptor.

   atomic_flag_works can only be used to make a file descriptor
   non-inheritable: atomic_flag_works must be NULL if inheritable=1. */
int
_Py_set_inheritable(int fd, int inheritable, int *atomic_flag_works)
{
    return set_inheritable(fd, inheritable, 1, atomic_flag_works);
}

/* Same as _Py_set_inheritable() but on error, set errno and
   don't raise an exception.
   This function is async-signal-safe. */
int
_Py_set_inheritable_async_safe(int fd, int inheritable, int *atomic_flag_works)
{
    return set_inheritable(fd, inheritable, 0, atomic_flag_works);
}

static int
_Py_open_impl(const char *pathname, int flags, int gil_held)
{
    int fd;
    int async_err = 0;
#ifndef MS_WINDOWS
    int *atomic_flag_works;
#endif

#ifdef MS_WINDOWS
    flags |= O_NOINHERIT;
#elif defined(O_CLOEXEC)
    atomic_flag_works = &_Py_open_cloexec_works;
    flags |= O_CLOEXEC;
#else
    atomic_flag_works = NULL;
#endif

    if (gil_held) {
        PyObject *pathname_obj = PyUnicode_DecodeFSDefault(pathname);
        if (pathname_obj == NULL) {
            return -1;
        }
        if (PySys_Audit("open", "OOi", pathname_obj, Py_None, flags) < 0) {
            Py_DECREF(pathname_obj);
            return -1;
        }

        do {
            Py_BEGIN_ALLOW_THREADS
            fd = open(pathname, flags);
            Py_END_ALLOW_THREADS
        } while (fd < 0
                 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
        if (async_err) {
            Py_DECREF(pathname_obj);
            return -1;
        }
        if (fd < 0) {
            PyErr_SetFromErrnoWithFilenameObjects(PyExc_OSError, pathname_obj, NULL);
            Py_DECREF(pathname_obj);
            return -1;
        }
        Py_DECREF(pathname_obj);
    }
    else {
        fd = open(pathname, flags);
        if (fd < 0)
            return -1;
    }

#ifndef MS_WINDOWS
    if (set_inheritable(fd, 0, gil_held, atomic_flag_works) < 0) {
        close(fd);
        return -1;
    }
#endif

    return fd;
}

/* Open a file with the specified flags (wrapper to open() function).
   Return a file descriptor on success. Raise an exception and return -1 on
   error.

   The file descriptor is created non-inheritable.

   When interrupted by a signal (open() fails with EINTR), retry the syscall,
   except if the Python signal handler raises an exception.

   Release the GIL to call open(). The caller must hold the GIL. */
int
_Py_open(const char *pathname, int flags)
{
    /* _Py_open() must be called with the GIL held. */
    assert(PyGILState_Check());
    return _Py_open_impl(pathname, flags, 1);
}

/* Open a file with the specified flags (wrapper to open() function).
   Return a file descriptor on success. Set errno and return -1 on error.

   The file descriptor is created non-inheritable.

   If interrupted by a signal, fail with EINTR. */
int
_Py_open_noraise(const char *pathname, int flags)
{
    return _Py_open_impl(pathname, flags, 0);
}

/* Open a file. Use _wfopen() on Windows, encode the path to the locale
   encoding and use fopen() otherwise.

   The file descriptor is created non-inheritable.

   If interrupted by a signal, fail with EINTR. */
FILE *
_Py_wfopen(const wchar_t *path, const wchar_t *mode)
{
    FILE *f;
    if (PySys_Audit("open", "uui", path, mode, 0) < 0) {
        return NULL;
    }
#ifndef MS_WINDOWS
    char *cpath;
    char cmode[10];
    size_t r;
    r = wcstombs(cmode, mode, 10);
    if (r == DECODE_ERROR || r >= 10) {
        errno = EINVAL;
        return NULL;
    }
    cpath = _Py_EncodeLocaleRaw(path, NULL);
    if (cpath == NULL) {
        return NULL;
    }
    f = fopen(cpath, cmode);
    PyMem_RawFree(cpath);
#else
    f = _wfopen(path, mode);
#endif
    if (f == NULL)
        return NULL;
    if (make_non_inheritable(fileno(f)) < 0) {
        fclose(f);
        return NULL;
    }
    return f;
}


/* Open a file. Call _wfopen() on Windows, or encode the path to the filesystem
   encoding and call fopen() otherwise.

   Return the new file object on success. Raise an exception and return NULL
   on error.

   The file descriptor is created non-inheritable.

   When interrupted by a signal (open() fails with EINTR), retry the syscall,
   except if the Python signal handler raises an exception.

   Release the GIL to call _wfopen() or fopen(). The caller must hold
   the GIL. */
FILE*
_Py_fopen_obj(PyObject *path, const char *mode)
{
    FILE *f;
    int async_err = 0;
#ifdef MS_WINDOWS
    wchar_t wmode[10];
    int usize;

    assert(PyGILState_Check());

    if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
        return NULL;
    }
    if (!PyUnicode_Check(path)) {
        PyErr_Format(PyExc_TypeError,
                     "str file path expected under Windows, got %R",
                     Py_TYPE(path));
        return NULL;
    }

    wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
    if (wpath == NULL)
        return NULL;

    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1,
                                wmode, Py_ARRAY_LENGTH(wmode));
    if (usize == 0) {
        PyErr_SetFromWindowsErr(0);
        PyMem_Free(wpath);
        return NULL;
    }

    do {
        Py_BEGIN_ALLOW_THREADS
        f = _wfopen(wpath, wmode);
        Py_END_ALLOW_THREADS
    } while (f == NULL
             && errno == EINTR && !(async_err = PyErr_CheckSignals()));
    PyMem_Free(wpath);
#else
    PyObject *bytes;
    const char *path_bytes;

    assert(PyGILState_Check());

    if (!PyUnicode_FSConverter(path, &bytes))
        return NULL;
    path_bytes = PyBytes_AS_STRING(bytes);

    if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
        Py_DECREF(bytes);
        return NULL;
    }

    do {
        Py_BEGIN_ALLOW_THREADS
        f = fopen(path_bytes, mode);
        Py_END_ALLOW_THREADS
    } while (f == NULL
             && errno == EINTR && !(async_err = PyErr_CheckSignals()));

    Py_DECREF(bytes);
#endif
    if (async_err)
        return NULL;

    if (f == NULL) {
        PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, path);
        return NULL;
    }

    if (set_inheritable(fileno(f), 0, 1, NULL) < 0) {
        fclose(f);
        return NULL;
    }
    return f;
}

/* Read count bytes from fd into buf.

   On success, return the number of read bytes, it can be lower than count.
   If the current file offset is at or past the end of file, no bytes are read,
   and read() returns zero.

   On error, raise an exception, set errno and return -1.

   When interrupted by a signal (read() fails with EINTR), retry the syscall.
   If the Python signal handler raises an exception, the function returns -1
   (the syscall is not retried).

   Release the GIL to call read(). The caller must hold the GIL. */
Py_ssize_t
_Py_read(int fd, void *buf, size_t count)
{
    Py_ssize_t n;
    int err;
    int async_err = 0;

    assert(PyGILState_Check());

    /* _Py_read() must not be called with an exception set, otherwise the
     * caller may think that read() was interrupted by a signal and the signal
     * handler raised an exception. */
    assert(!PyErr_Occurred());

    if (count > _PY_READ_MAX) {
        count = _PY_READ_MAX;
    }

    _Py_BEGIN_SUPPRESS_IPH
    do {
        Py_BEGIN_ALLOW_THREADS
        errno = 0;
#ifdef MS_WINDOWS
        _doserrno = 0;
        n = read(fd, buf, (int)count);
        // read() on a non-blocking empty pipe fails with EINVAL, which is
        // mapped from the Windows error code ERROR_NO_DATA.
        if (n < 0 && errno == EINVAL) {
            if (_doserrno == ERROR_NO_DATA) {
                errno = EAGAIN;
            }
        }
#else
        n = read(fd, buf, count);
#endif
        /* save/restore errno because PyErr_CheckSignals()
         * and PyErr_SetFromErrno() can modify it */
        err = errno;
        Py_END_ALLOW_THREADS
    } while (n < 0 && err == EINTR &&
            !(async_err = PyErr_CheckSignals()));
    _Py_END_SUPPRESS_IPH

    if (async_err) {
        /* read() was interrupted by a signal (failed with EINTR)
         * and the Python signal handler raised an exception */
        errno = err;
        assert(errno == EINTR && PyErr_Occurred());
        return -1;
    }
    if (n < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        errno = err;
        return -1;
    }

    return n;
}

static Py_ssize_t
_Py_write_impl(int fd, const void *buf, size_t count, int gil_held)
{
    Py_ssize_t n;
    int err;
    int async_err = 0;

    _Py_BEGIN_SUPPRESS_IPH
#ifdef MS_WINDOWS
    if (count > 32767) {
        /* Issue #11395: the Windows console returns an error (12: not
           enough space error) on writing into stdout if stdout mode is
           binary and the length is greater than 66,000 bytes (or less,
           depending on heap usage). */
        if (gil_held) {
            Py_BEGIN_ALLOW_THREADS
            if (isatty(fd)) {
                count = 32767;
            }
            Py_END_ALLOW_THREADS
        } else {
            if (isatty(fd)) {
                count = 32767;
            }
        }
    }

#endif
    if (count > _PY_WRITE_MAX) {
        count = _PY_WRITE_MAX;
    }

    if (gil_held) {
        do {
            Py_BEGIN_ALLOW_THREADS
            errno = 0;
#ifdef MS_WINDOWS
            // write() on a non-blocking pipe fails with ENOSPC on Windows if
            // the pipe lacks available space for the entire buffer.
            int c = (int)count;
            do {
                _doserrno = 0;
                n = write(fd, buf, c);
                if (n >= 0 || errno != ENOSPC || _doserrno != 0) {
                    break;
                }
                errno = EAGAIN;
                c /= 2;
            } while (c > 0);
#else
            n = write(fd, buf, count);
#endif
            /* save/restore errno because PyErr_CheckSignals()
             * and PyErr_SetFromErrno() can modify it */
            err = errno;
            Py_END_ALLOW_THREADS
        } while (n < 0 && err == EINTR &&
                !(async_err = PyErr_CheckSignals()));
    }
    else {
        do {
            errno = 0;
#ifdef MS_WINDOWS
            // write() on a non-blocking pipe fails with ENOSPC on Windows if
            // the pipe lacks available space for the entire buffer.
            int c = (int)count;
            do {
                _doserrno = 0;
                n = write(fd, buf, c);
                if (n >= 0 || errno != ENOSPC || _doserrno != 0) {
                    break;
                }
                errno = EAGAIN;
                c /= 2;
            } while (c > 0);
#else
            n = write(fd, buf, count);
#endif
            err = errno;
        } while (n < 0 && err == EINTR);
    }
    _Py_END_SUPPRESS_IPH

    if (async_err) {
        /* write() was interrupted by a signal (failed with EINTR)
           and the Python signal handler raised an exception (if gil_held is
           nonzero). */
        errno = err;
        assert(errno == EINTR && (!gil_held || PyErr_Occurred()));
        return -1;
    }
    if (n < 0) {
        if (gil_held)
            PyErr_SetFromErrno(PyExc_OSError);
        errno = err;
        return -1;
    }

    return n;
}

/* Write count bytes of buf into fd.

   On success, return the number of written bytes, it can be lower than count
   including 0. On error, raise an exception, set errno and return -1.

   When interrupted by a signal (write() fails with EINTR), retry the syscall.
   If the Python signal handler raises an exception, the function returns -1
   (the syscall is not retried).

   Release the GIL to call write(). The caller must hold the GIL. */
Py_ssize_t
_Py_write(int fd, const void *buf, size_t count)
{
    assert(PyGILState_Check());

    /* _Py_write() must not be called with an exception set, otherwise the
     * caller may think that write() was interrupted by a signal and the signal
     * handler raised an exception. */
    assert(!PyErr_Occurred());

    return _Py_write_impl(fd, buf, count, 1);
}

/* Write count bytes of buf into fd.
 *
 * On success, return the number of written bytes, it can be lower than count
 * including 0. On error, set errno and return -1.
 *
 * When interrupted by a signal (write() fails with EINTR), retry the syscall
 * without calling the Python signal handler. */
Py_ssize_t
_Py_write_noraise(int fd, const void *buf, size_t count)
{
    return _Py_write_impl(fd, buf, count, 0);
}

#ifdef HAVE_READLINK

/* Read value of symbolic link. Encode the path to the locale encoding, decode
   the result from the locale encoding.

   Return -1 on encoding error, on readlink() error, if the internal buffer is
   too short, on decoding error, or if 'buf' is too short. */
int
_Py_wreadlink(const wchar_t *path, wchar_t *buf, size_t buflen)
{
    char *cpath;
    char cbuf[MAXPATHLEN];
    size_t cbuf_len = Py_ARRAY_LENGTH(cbuf);
    wchar_t *wbuf;
    Py_ssize_t res;
    size_t r1;

    cpath = _Py_EncodeLocaleRaw(path, NULL);
    if (cpath == NULL) {
        errno = EINVAL;
        return -1;
    }
    res = readlink(cpath, cbuf, cbuf_len);
    PyMem_RawFree(cpath);
    if (res == -1) {
        return -1;
    }
    if ((size_t)res == cbuf_len) {
        errno = EINVAL;
        return -1;
    }
    cbuf[res] = '\0'; /* buf will be null terminated */
    wbuf = Py_DecodeLocale(cbuf, &r1);
    if (wbuf == NULL) {
        errno = EINVAL;
        return -1;
    }
    /* wbuf must have space to store the trailing NUL character */
    if (buflen <= r1) {
        PyMem_RawFree(wbuf);
        errno = EINVAL;
        return -1;
    }
    wcsncpy(buf, wbuf, buflen);
    PyMem_RawFree(wbuf);
    return (int)r1;
}
#endif

#ifdef HAVE_REALPATH

/* Return the canonicalized absolute pathname. Encode path to the locale
   encoding, decode the result from the locale encoding.

   Return NULL on encoding error, realpath() error, decoding error
   or if 'resolved_path' is too short. */
wchar_t*
_Py_wrealpath(const wchar_t *path,
              wchar_t *resolved_path, size_t resolved_path_len)
{
    char *cpath;
    char cresolved_path[MAXPATHLEN];
    wchar_t *wresolved_path;
    char *res;
    size_t r;
    cpath = _Py_EncodeLocaleRaw(path, NULL);
    if (cpath == NULL) {
        errno = EINVAL;
        return NULL;
    }
    res = realpath(cpath, cresolved_path);
    PyMem_RawFree(cpath);
    if (res == NULL)
        return NULL;

    wresolved_path = Py_DecodeLocale(cresolved_path, &r);
    if (wresolved_path == NULL) {
        errno = EINVAL;
        return NULL;
    }
    /* wresolved_path must have space to store the trailing NUL character */
    if (resolved_path_len <= r) {
        PyMem_RawFree(wresolved_path);
        errno = EINVAL;
        return NULL;
    }
    wcsncpy(resolved_path, wresolved_path, resolved_path_len);
    PyMem_RawFree(wresolved_path);
    return resolved_path;
}
#endif


int
_Py_isabs(const wchar_t *path)
{
#ifdef MS_WINDOWS
    const wchar_t *tail;
    HRESULT hr = PathCchSkipRoot(path, &tail);
    if (FAILED(hr) || path == tail) {
        return 0;
    }
    if (tail == &path[1] && (path[0] == SEP || path[0] == ALTSEP)) {
        // Exclude paths with leading SEP
        return 0;
    }
    if (tail == &path[2] && path[1] == L':') {
        // Exclude drive-relative paths (e.g. C:filename.ext)
        return 0;
    }
    return 1;
#else
    return (path[0] == SEP);
#endif
}


/* Get an absolute path.
   On error (ex: fail to get the current directory), return -1.
   On memory allocation failure, set *abspath_p to NULL and return 0.
   On success, return a newly allocated to *abspath_p to and return 0.
   The string must be freed by PyMem_RawFree(). */
int
_Py_abspath(const wchar_t *path, wchar_t **abspath_p)
{
    if (path[0] == '\0' || !wcscmp(path, L".")) {
        wchar_t cwd[MAXPATHLEN + 1];
        cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
        if (!_Py_wgetcwd(cwd, Py_ARRAY_LENGTH(cwd) - 1)) {
            /* unable to get the current directory */
            return -1;
        }
        *abspath_p = _PyMem_RawWcsdup(cwd);
        return 0;
    }

    if (_Py_isabs(path)) {
        *abspath_p = _PyMem_RawWcsdup(path);
        return 0;
    }

#ifdef MS_WINDOWS
    return _PyOS_getfullpathname(path, abspath_p);
#else
    wchar_t cwd[MAXPATHLEN + 1];
    cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
    if (!_Py_wgetcwd(cwd, Py_ARRAY_LENGTH(cwd) - 1)) {
        /* unable to get the current directory */
        return -1;
    }

    size_t cwd_len = wcslen(cwd);
    size_t path_len = wcslen(path);
    size_t len = cwd_len + 1 + path_len + 1;
    if (len <= (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t)) {
        *abspath_p = PyMem_RawMalloc(len * sizeof(wchar_t));
    }
    else {
        *abspath_p = NULL;
    }
    if (*abspath_p == NULL) {
        return 0;
    }

    wchar_t *abspath = *abspath_p;
    memcpy(abspath, cwd, cwd_len * sizeof(wchar_t));
    abspath += cwd_len;

    *abspath = (wchar_t)SEP;
    abspath++;

    memcpy(abspath, path, path_len * sizeof(wchar_t));
    abspath += path_len;

    *abspath = 0;
    return 0;
#endif
}

// The Windows Games API family implements the PathCch* APIs in the Xbox OS,
// but does not expose them yet. Load them dynamically until
// 1) they are officially exposed
// 2) we stop supporting older versions of the GDK which do not expose them
#if defined(MS_WINDOWS_GAMES) && !defined(MS_WINDOWS_DESKTOP)
HRESULT
PathCchSkipRoot(const wchar_t *path, const wchar_t **rootEnd)
{
    static int initialized = 0;
    typedef HRESULT(__stdcall *PPathCchSkipRoot) (PCWSTR pszPath,
                                                  PCWSTR *ppszRootEnd);
    static PPathCchSkipRoot _PathCchSkipRoot;

    if (initialized == 0) {
        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
        if (pathapi) {
            _PathCchSkipRoot = (PPathCchSkipRoot)GetProcAddress(
                pathapi, "PathCchSkipRoot");
        }
        else {
            _PathCchSkipRoot = NULL;
        }
        initialized = 1;
    }

    if (!_PathCchSkipRoot) {
        return E_NOINTERFACE;
    }

    return _PathCchSkipRoot(path, rootEnd);
}

static HRESULT
PathCchCombineEx(wchar_t *buffer, size_t bufsize, const wchar_t *dirname,
                 const wchar_t *relfile, unsigned long flags)
{
    static int initialized = 0;
    typedef HRESULT(__stdcall *PPathCchCombineEx) (PWSTR pszPathOut,
                                                   size_t cchPathOut,
                                                   PCWSTR pszPathIn,
                                                   PCWSTR pszMore,
                                                   unsigned long dwFlags);
    static PPathCchCombineEx _PathCchCombineEx;

    if (initialized == 0) {
        HMODULE pathapi = LoadLibraryExW(L"api-ms-win-core-path-l1-1-0.dll", NULL,
                                         LOAD_LIBRARY_SEARCH_SYSTEM32);
        if (pathapi) {
            _PathCchCombineEx = (PPathCchCombineEx)GetProcAddress(
                pathapi, "PathCchCombineEx");
        }
        else {
            _PathCchCombineEx = NULL;
        }
        initialized = 1;
    }

    if (!_PathCchCombineEx) {
        return E_NOINTERFACE;
    }

    return _PathCchCombineEx(buffer, bufsize, dirname, relfile, flags);
}

#endif /* defined(MS_WINDOWS_GAMES) && !defined(MS_WINDOWS_DESKTOP) */

// The caller must ensure "buffer" is big enough.
static int
join_relfile(wchar_t *buffer, size_t bufsize,
             const wchar_t *dirname, const wchar_t *relfile)
{
#ifdef MS_WINDOWS
    if (FAILED(PathCchCombineEx(buffer, bufsize, dirname, relfile,
        PATHCCH_ALLOW_LONG_PATHS))) {
        return -1;
    }
#else
    assert(!_Py_isabs(relfile));
    size_t dirlen = wcslen(dirname);
    size_t rellen = wcslen(relfile);
    size_t maxlen = bufsize - 1;
    if (maxlen > MAXPATHLEN || dirlen >= maxlen || rellen >= maxlen - dirlen) {
        return -1;
    }
    if (dirlen == 0) {
        // We do not add a leading separator.
        wcscpy(buffer, relfile);
    }
    else {
        if (dirname != buffer) {
            wcscpy(buffer, dirname);
        }
        size_t relstart = dirlen;
        if (dirlen > 1 && dirname[dirlen - 1] != SEP) {
            buffer[dirlen] = SEP;
            relstart += 1;
        }
        wcscpy(&buffer[relstart], relfile);
    }
#endif
    return 0;
}

/* Join the two paths together, like os.path.join().  Return NULL
   if memory could not be allocated.  The caller is responsible
   for calling PyMem_RawFree() on the result. */
wchar_t *
_Py_join_relfile(const wchar_t *dirname, const wchar_t *relfile)
{
    assert(dirname != NULL && relfile != NULL);
#ifndef MS_WINDOWS
    assert(!_Py_isabs(relfile));
#endif
    size_t maxlen = wcslen(dirname) + 1 + wcslen(relfile);
    size_t bufsize = maxlen + 1;
    wchar_t *filename = PyMem_RawMalloc(bufsize * sizeof(wchar_t));
    if (filename == NULL) {
        return NULL;
    }
    assert(wcslen(dirname) < MAXPATHLEN);
    assert(wcslen(relfile) < MAXPATHLEN - wcslen(dirname));
    join_relfile(filename, bufsize, dirname, relfile);
    return filename;
}

/* Join the two paths together, like os.path.join().
     dirname: the target buffer with the dirname already in place,
              including trailing NUL
     relfile: this must be a relative path
     bufsize: total allocated size of the buffer
   Return -1 if anything is wrong with the path lengths. */
int
_Py_add_relfile(wchar_t *dirname, const wchar_t *relfile, size_t bufsize)
{
    assert(dirname != NULL && relfile != NULL);
    assert(bufsize > 0);
    return join_relfile(dirname, bufsize, dirname, relfile);
}


size_t
_Py_find_basename(const wchar_t *filename)
{
    for (size_t i = wcslen(filename); i > 0; --i) {
        if (filename[i] == SEP) {
            return i + 1;
        }
    }
    return 0;
}

/* In-place path normalisation. Returns the start of the normalized
   path, which will be within the original buffer. Guaranteed to not
   make the path longer, and will not fail. 'size' is the length of
   the path, if known. If -1, the first null character will be assumed
   to be the end of the path. */
wchar_t *
_Py_normpath(wchar_t *path, Py_ssize_t size)
{
    if (!path[0] || size == 0) {
        return path;
    }
    wchar_t *pEnd = size >= 0 ? &path[size] : NULL;
    wchar_t *p1 = path;     // sequentially scanned address in the path
    wchar_t *p2 = path;     // destination of a scanned character to be ljusted
    wchar_t *minP2 = path;  // the beginning of the destination range
    wchar_t lastC = L'\0';  // the last ljusted character, p2[-1] in most cases

#define IS_END(x) (pEnd ? (x) == pEnd : !*(x))
#ifdef ALTSEP
#define IS_SEP(x) (*(x) == SEP || *(x) == ALTSEP)
#else
#define IS_SEP(x) (*(x) == SEP)
#endif
#define SEP_OR_END(x) (IS_SEP(x) || IS_END(x))

    // Skip leading '.\'
    if (p1[0] == L'.' && IS_SEP(&p1[1])) {
        path = &path[2];
        while (IS_SEP(path) && !IS_END(path)) {
            path++;
        }
        p1 = p2 = minP2 = path;
        lastC = SEP;
    }
#ifdef MS_WINDOWS
    // Skip past drive segment and update minP2
    else if (p1[0] && p1[1] == L':') {
        *p2++ = *p1++;
        *p2++ = *p1++;
        minP2 = p2;
        lastC = L':';
    }
    // Skip past all \\-prefixed paths, including \\?\, \\.\,
    // and network paths, including the first segment.
    else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1])) {
        int sepCount = 2;
        *p2++ = SEP;
        *p2++ = SEP;
        p1 += 2;
        for (; !IS_END(p1) && sepCount; ++p1) {
            if (IS_SEP(p1)) {
                --sepCount;
                *p2++ = lastC = SEP;
            } else {
                *p2++ = lastC = *p1;
            }
        }
        if (sepCount) {
            minP2 = p2;      // Invalid path
        } else {
            minP2 = p2 - 1;  // Absolute path has SEP at minP2
        }
    }
#else
    // Skip past two leading SEPs
    else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1]) && !IS_SEP(&p1[2])) {
        *p2++ = *p1++;
        *p2++ = *p1++;
        minP2 = p2 - 1;  // Absolute path has SEP at minP2
        lastC = SEP;
    }
#endif /* MS_WINDOWS */

    /* if pEnd is specified, check that. Else, check for null terminator */
    for (; !IS_END(p1); ++p1) {
        wchar_t c = *p1;
#ifdef ALTSEP
        if (c == ALTSEP) {
            c = SEP;
        }
#endif
        if (lastC == SEP) {
            if (c == L'.') {
                int sep_at_1 = SEP_OR_END(&p1[1]);
                int sep_at_2 = !sep_at_1 && SEP_OR_END(&p1[2]);
                if (sep_at_2 && p1[1] == L'.') {
                    wchar_t *p3 = p2;
                    while (p3 != minP2 && *--p3 == SEP) { }
                    while (p3 != minP2 && *(p3 - 1) != SEP) { --p3; }
                    if (p2 == minP2
                        || (p3[0] == L'.' && p3[1] == L'.' && IS_SEP(&p3[2])))
                    {
                        // Previous segment is also ../, so append instead.
                        // Relative path does not absorb ../ at minP2 as well.
                        *p2++ = L'.';
                        *p2++ = L'.';
                        lastC = L'.';
                    } else if (p3[0] == SEP) {
                        // Absolute path, so absorb segment
                        p2 = p3 + 1;
                    } else {
                        p2 = p3;
                    }
                    p1 += 1;
                } else if (sep_at_1) {
                } else {
                    *p2++ = lastC = c;
                }
            } else if (c == SEP) {
            } else {
                *p2++ = lastC = c;
            }
        } else {
            *p2++ = lastC = c;
        }
    }
    *p2 = L'\0';
    if (p2 != minP2) {
        while (--p2 != minP2 && *p2 == SEP) {
            *p2 = L'\0';
        }
    }
#undef SEP_OR_END
#undef IS_SEP
#undef IS_END
    return path;
}


/* Get the current directory. buflen is the buffer size in wide characters
   including the null character. Decode the path from the locale encoding.

   Return NULL on getcwd() error, on decoding error, or if 'buf' is
   too short. */
wchar_t*
_Py_wgetcwd(wchar_t *buf, size_t buflen)
{
#ifdef MS_WINDOWS
    int ibuflen = (int)Py_MIN(buflen, INT_MAX);
    return _wgetcwd(buf, ibuflen);
#else
    char fname[MAXPATHLEN];
    wchar_t *wname;
    size_t len;

    if (getcwd(fname, Py_ARRAY_LENGTH(fname)) == NULL)
        return NULL;
    wname = Py_DecodeLocale(fname, &len);
    if (wname == NULL)
        return NULL;
    /* wname must have space to store the trailing NUL character */
    if (buflen <= len) {
        PyMem_RawFree(wname);
        return NULL;
    }
    wcsncpy(buf, wname, buflen);
    PyMem_RawFree(wname);
    return buf;
#endif
}

/* Duplicate a file descriptor. The new file descriptor is created as
   non-inheritable. Return a new file descriptor on success, raise an OSError
   exception and return -1 on error.

   The GIL is released to call dup(). The caller must hold the GIL. */
int
_Py_dup(int fd)
{
#ifdef MS_WINDOWS
    HANDLE handle;
#endif

    assert(PyGILState_Check());

#ifdef MS_WINDOWS
    handle = _Py_get_osfhandle(fd);
    if (handle == INVALID_HANDLE_VALUE)
        return -1;

    Py_BEGIN_ALLOW_THREADS
    _Py_BEGIN_SUPPRESS_IPH
    fd = dup(fd);
    _Py_END_SUPPRESS_IPH
    Py_END_ALLOW_THREADS
    if (fd < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    if (_Py_set_inheritable(fd, 0, NULL) < 0) {
        _Py_BEGIN_SUPPRESS_IPH
        close(fd);
        _Py_END_SUPPRESS_IPH
        return -1;
    }
#elif defined(HAVE_FCNTL_H) && defined(F_DUPFD_CLOEXEC)
    Py_BEGIN_ALLOW_THREADS
    _Py_BEGIN_SUPPRESS_IPH
    fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
    _Py_END_SUPPRESS_IPH
    Py_END_ALLOW_THREADS
    if (fd < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

#elif HAVE_DUP
    Py_BEGIN_ALLOW_THREADS
    _Py_BEGIN_SUPPRESS_IPH
    fd = dup(fd);
    _Py_END_SUPPRESS_IPH
    Py_END_ALLOW_THREADS
    if (fd < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    if (_Py_set_inheritable(fd, 0, NULL) < 0) {
        _Py_BEGIN_SUPPRESS_IPH
        close(fd);
        _Py_END_SUPPRESS_IPH
        return -1;
    }
#else
    errno = ENOTSUP;
    PyErr_SetFromErrno(PyExc_OSError);
    return -1;
#endif
    return fd;
}

#ifndef MS_WINDOWS
/* Get the blocking mode of the file descriptor.
   Return 0 if the O_NONBLOCK flag is set, 1 if the flag is cleared,
   raise an exception and return -1 on error. */
int
_Py_get_blocking(int fd)
{
    int flags;
    _Py_BEGIN_SUPPRESS_IPH
    flags = fcntl(fd, F_GETFL, 0);
    _Py_END_SUPPRESS_IPH
    if (flags < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        return -1;
    }

    return !(flags & O_NONBLOCK);
}

/* Set the blocking mode of the specified file descriptor.

   Set the O_NONBLOCK flag if blocking is False, clear the O_NONBLOCK flag
   otherwise.

   Return 0 on success, raise an exception and return -1 on error. */
int
_Py_set_blocking(int fd, int blocking)
{
/* bpo-41462: On VxWorks, ioctl(FIONBIO) only works on sockets.
   Use fcntl() instead. */
#if defined(HAVE_SYS_IOCTL_H) && defined(FIONBIO) && !defined(__VXWORKS__)
    int arg = !blocking;
    if (ioctl(fd, FIONBIO, &arg) < 0)
        goto error;
#else
    int flags, res;

    _Py_BEGIN_SUPPRESS_IPH
    flags = fcntl(fd, F_GETFL, 0);
    if (flags >= 0) {
        if (blocking)
            flags = flags & (~O_NONBLOCK);
        else
            flags = flags | O_NONBLOCK;

        res = fcntl(fd, F_SETFL, flags);
    } else {
        res = -1;
    }
    _Py_END_SUPPRESS_IPH

    if (res < 0)
        goto error;
#endif
    return 0;

error:
    PyErr_SetFromErrno(PyExc_OSError);
    return -1;
}
#else   /* MS_WINDOWS */
int
_Py_get_blocking(int fd)
{
    HANDLE handle;
    DWORD mode;
    BOOL success;

    handle = _Py_get_osfhandle(fd);
    if (handle == INVALID_HANDLE_VALUE) {
        return -1;
    }

    Py_BEGIN_ALLOW_THREADS
    success = GetNamedPipeHandleStateW(handle, &mode,
                                       NULL, NULL, NULL, NULL, 0);
    Py_END_ALLOW_THREADS

    if (!success) {
        PyErr_SetFromWindowsErr(0);
        return -1;
    }

    return !(mode & PIPE_NOWAIT);
}

int
_Py_set_blocking(int fd, int blocking)
{
    HANDLE handle;
    DWORD mode;
    BOOL success;

    handle = _Py_get_osfhandle(fd);
    if (handle == INVALID_HANDLE_VALUE) {
        return -1;
    }

    Py_BEGIN_ALLOW_THREADS
    success = GetNamedPipeHandleStateW(handle, &mode,
                                       NULL, NULL, NULL, NULL, 0);
    if (success) {
        if (blocking) {
            mode &= ~PIPE_NOWAIT;
        }
        else {
            mode |= PIPE_NOWAIT;
        }
        success = SetNamedPipeHandleState(handle, &mode, NULL, NULL);
    }
    Py_END_ALLOW_THREADS

    if (!success) {
        PyErr_SetFromWindowsErr(0);
        return -1;
    }
    return 0;
}

void*
_Py_get_osfhandle_noraise(int fd)
{
    void *handle;
    _Py_BEGIN_SUPPRESS_IPH
    handle = (void*)_get_osfhandle(fd);
    _Py_END_SUPPRESS_IPH
    return handle;
}

void*
_Py_get_osfhandle(int fd)
{
    void *handle = _Py_get_osfhandle_noraise(fd);
    if (handle == INVALID_HANDLE_VALUE)
        PyErr_SetFromErrno(PyExc_OSError);

    return handle;
}

int
_Py_open_osfhandle_noraise(void *handle, int flags)
{
    int fd;
    _Py_BEGIN_SUPPRESS_IPH
    fd = _open_osfhandle((intptr_t)handle, flags);
    _Py_END_SUPPRESS_IPH
    return fd;
}

int
_Py_open_osfhandle(void *handle, int flags)
{
    int fd = _Py_open_osfhandle_noraise(handle, flags);
    if (fd == -1)
        PyErr_SetFromErrno(PyExc_OSError);

    return fd;
}
#endif  /* MS_WINDOWS */

int
_Py_GetLocaleconvNumeric(struct lconv *lc,
                         PyObject **decimal_point, PyObject **thousands_sep)
{
    assert(decimal_point != NULL);
    assert(thousands_sep != NULL);

#ifndef MS_WINDOWS
    int change_locale = 0;
    if ((strlen(lc->decimal_point) > 1 || ((unsigned char)lc->decimal_point[0]) > 127)) {
        change_locale = 1;
    }
    if ((strlen(lc->thousands_sep) > 1 || ((unsigned char)lc->thousands_sep[0]) > 127)) {
        change_locale = 1;
    }

    /* Keep a copy of the LC_CTYPE locale */
    char *oldloc = NULL, *loc = NULL;
    if (change_locale) {
        oldloc = setlocale(LC_CTYPE, NULL);
        if (!oldloc) {
            PyErr_SetString(PyExc_RuntimeWarning,
                            "failed to get LC_CTYPE locale");
            return -1;
        }

        oldloc = _PyMem_Strdup(oldloc);
        if (!oldloc) {
            PyErr_NoMemory();
            return -1;
        }

        loc = setlocale(LC_NUMERIC, NULL);
        if (loc != NULL && strcmp(loc, oldloc) == 0) {
            loc = NULL;
        }

        if (loc != NULL) {
            /* Only set the locale temporarily the LC_CTYPE locale
               if LC_NUMERIC locale is different than LC_CTYPE locale and
               decimal_point and/or thousands_sep are non-ASCII or longer than
               1 byte */
            setlocale(LC_CTYPE, loc);
        }
    }

#define GET_LOCALE_STRING(ATTR) PyUnicode_DecodeLocale(lc->ATTR, NULL)
#else /* MS_WINDOWS */
/* Use _W_* fields of Windows strcut lconv */
#define GET_LOCALE_STRING(ATTR) PyUnicode_FromWideChar(lc->_W_ ## ATTR, -1)
#endif /* MS_WINDOWS */

    int res = -1;

    *decimal_point = GET_LOCALE_STRING(decimal_point);
    if (*decimal_point == NULL) {
        goto done;
    }

    *thousands_sep = GET_LOCALE_STRING(thousands_sep);
    if (*thousands_sep == NULL) {
        goto done;
    }

    res = 0;

done:
#ifndef MS_WINDOWS
    if (loc != NULL) {
        setlocale(LC_CTYPE, oldloc);
    }
    PyMem_Free(oldloc);
#endif
    return res;

#undef GET_LOCALE_STRING
}

/* Our selection logic for which function to use is as follows:
 * 1. If close_range(2) is available, always prefer that; it's better for
 *    contiguous ranges like this than fdwalk(3) which entails iterating over
 *    the entire fd space and simply doing nothing for those outside the range.
 * 2. If closefrom(2) is available, we'll attempt to use that next if we're
 *    closing up to sysconf(_SC_OPEN_MAX).
 * 2a. Fallback to fdwalk(3) if we're not closing up to sysconf(_SC_OPEN_MAX),
 *    as that will be more performant if the range happens to have any chunk of
 *    non-opened fd in the middle.
 * 2b. If fdwalk(3) isn't available, just do a plain close(2) loop.
 */
#ifdef __FreeBSD__
#  define USE_CLOSEFROM
#endif /* __FreeBSD__ */

#ifdef HAVE_FDWALK
#  define USE_FDWALK
#endif /* HAVE_FDWALK */

#ifdef USE_FDWALK
static int
_fdwalk_close_func(void *lohi, int fd)
{
    int lo = ((int *)lohi)[0];
    int hi = ((int *)lohi)[1];

    if (fd >= hi) {
        return 1;
    }
    else if (fd >= lo) {
        /* Ignore errors */
        (void)close(fd);
    }
    return 0;
}
#endif /* USE_FDWALK */

/* Closes all file descriptors in [first, last], ignoring errors. */
void
_Py_closerange(int first, int last)
{
    first = Py_MAX(first, 0);
    _Py_BEGIN_SUPPRESS_IPH
#ifdef HAVE_CLOSE_RANGE
    if (close_range(first, last, 0) == 0) {
        /* close_range() ignores errors when it closes file descriptors.
         * Possible reasons of an error return are lack of kernel support
         * or denial of the underlying syscall by a seccomp sandbox on Linux.
         * Fallback to other methods in case of any error. */
    }
    else
#endif /* HAVE_CLOSE_RANGE */
#ifdef USE_CLOSEFROM
    if (last >= sysconf(_SC_OPEN_MAX)) {
        /* Any errors encountered while closing file descriptors are ignored */
        closefrom(first);
    }
    else
#endif /* USE_CLOSEFROM */
#ifdef USE_FDWALK
    {
        int lohi[2];
        lohi[0] = first;
        lohi[1] = last + 1;
        fdwalk(_fdwalk_close_func, lohi);
    }
#else
    {
        for (int i = first; i <= last; i++) {
            /* Ignore errors */
            (void)close(i);
        }
    }
#endif /* USE_FDWALK */
    _Py_END_SUPPRESS_IPH
}